Ureteral stone extractor



May l0, 195,5 T. A. DAvls URETERAL STONE EXTRACTOR Filed June 22, 1955INVENTOR. THOMAS A. DAVIS Bywiw- United States Patent() URETERAL STONEEXTRACTOR Thomas A. Davis, Portland, Oreg. Y Application .lune 22, 1953,Serial No. 363,105

3 Claims. (Cl. 12S-349) My invention relates to a ureteral stoneextractor and is particularly adapted for the removing of stones from aureter or for dilating the ureter.

There are ureteral stone extractors already on the market of thecatheter type, wherein the upper end or tip is looped back into the formof a loop. This requires considerable space to make this loop and in theuse of them it normally requires the advancement of it to the renalpelvis in order that there may be suiiicient space in which to form theloop.

In my device, the loop can 'be formed at any location within the ureterand a complete loop does not have to be formed so that considerablecontrol of the loop is had in my construction.

Furthermore, in the device in which the tip is looped back, the crossdiameter of the loop on Withdrawal into the ureter is depended upon therelationship between the diameter of the ureter and its degree ofcontraction, and the inherent elastic expansion of the loop. In mydevice there is complete control of the diameter or depth of the loop.

With the forming ot a loop on the end of the extractor, a tendency forthe same to hook into the tissue is always possible, causing injury, butwith my specially formed loop, this possibility is completelyeliminated.

With the present day device, the loop having once been formed andwithdrawn into the ureter, the loop cannot be released without danger ofdamage to the ureter. With my form of loop it can be released withoutinjury.

With the present type of extractor in which the end is formed into aloop, if upon withdrawal of the extractor to engage the calculus and thecalculus is not engaged, the extractor must be removed entirely from theureter, straightened out and again reinserted, repassed by the calculus,advanced to the renal pelvis and the entire operation repeated. it isusually diflcult to pass by the calculus.

With my device the extractor being withdrawn to engage the calculusunder cystoscopic vision, if the loop is seen to exit from the ureterwithout having engaged the calculus, the loop may be collapsed and theextractor readvanced to the proper position for re-forming the loop withease, because the upper end of the extractor is still above thecalculus, in the case of calculi in the lower end of the ureter, theusual location from which calculi has to be removed.

In my extractor, after the loop has been formed or while the stone isengaged or held within the loop, the upper end of the extractor catheterremaining extended up the ureter to a level above the calculus with theopenings in the tip above the level of the calculus, it may function asa catheter to drain the ureter above the level of the calculus or tointroduce contrast media for X-ray or medication, whereas the type inwhich the upper end or tip is looped over and formed in a return bendwill not function as a catheter.

With my type of extractor, the space required for it within the ureterwhile engaging, or after having engaged ICC the calculus, is less thanthat required for the type of extractor in which there is a loop formedby the end of the catheter being bent over into a loop. The spacerequired with my extractor is that of the width of the stone plus thewidth of one single diameter ofthe extractor catheter.

The primary object of my invention is to provide means for removingcalculi or stones from the ureter or to make conditions in the uretermore favorable for the passing of calculi down the ureter.

A further object of my invention is the providing of means Within thecatheter or tube for the forming of an olset or loop in the saidcatheter for expanding the ureter or directly removing the stones lodgedin the ureter.

Briefly, my invention comprises a tubular catheter havinfy means forforming a loop within the tube below its upper inner end or tip, thisloop being of such a design that the tip will not be looped back in theforming of the loop, but will remain extended up the ureter.

With my new and improved ureteral stone extractor, I can control thesize of the loop being used and the removing of the stone from theureter, also the stone can be easily released if desired.

A further object of my invention is to provide a device havingcharacteristics of a simple tube which will permit the injection offluids, or the removal of fluids from the ureter, as well as extractingforeign bodies.

Another object of my invention is to provide a device that may beinserted into a ureter with the ease, facility and safety of an ordinaryureteral catheter.

These and other incidental objects will be apparent from the followingdescription when read in connection with the accompanying drawing inwhich:

Figure l is a side view of an extractor catheter 0r tube, partiallybroken away for convenience of illustrating the principle of forming myinvention;

Figure 2 is a diagrammatic sectional lay-out of a bladder and ureterleading thereto, showing the position of the extractor catheter beforeforming a loop, part of the tube broken away for convenience ofillustration;

Figure 3 illustrates how l form a loop in the catheter or tube withinthe ureter, and

Figure 4 illustrates how the stone is removed by the loop formed in theextractor catheter or tube.

Referring now to the drawing, specifically to Figures 2 and 4, a sectionis shown through a bladder 1, having ureteral openings 2 providingcommunication with the ureters 3. A calculus or stone 4 is shown asbeing lodged within one of the ureters and must be removed.

My invention comprises an extractor catheter or flexible tube 5terminating in a tip 6 and having one or more openings 5A adjacent saidtip 6 and one or more pairs of apertures spaced from the tip 6. A threador wire 7 is threaded through the tube 5 and is passed out of the tubethrough said pair of apertures'to form with the tube a loop that isspaced from the tip 6. Specifically, the thread 7 is threaded up throughthe tube and out through an aperture 10, back into the tube through anaperture 8, out of the tube through an aperture 13, back in through anaperture 14 and out through an aperture 9, and back into the tubethrough an aperture 11 and threaded back down through the tube 5, thusproviding two strands of thread or wire, as indicated at 7A and 7B. Theobject of threading the thread or wire through the openings 13 and 14 isto provide an additional safety feature in case the tube would breakwhere being iiexed at the portions Wh-ich are weakened by the aperturesS, 9, 10 and 11, the

tip would still remain connected to the thread or wire, permitting it tobe removed from the ureter.

ln operation, referring to Figures 241, the tip 6 is inserted up throughthe bladder 1 and through one of the openings 2 into the respectiveureter 3 as shown in Figure 2. When the extractor catheter or tube is inplace within the ureter, the strands 7A and/or 7B are pulled throughsaid tube to the desired size, as shown in Figure 3. When the catheterwith this loop is pulled down through the ureter, it will grasp, snareor engage the stone 4, as shown in Figure 4, removing the same from theureter.

When the thread 7 is pulled down through the tube 5, a loop is formedbetween the pair of apertures 8 and 9 and/ or the pair of apertures 10and 11, as best illustrated in Figures 3 and 4. Openings 5A are formedin the tip of the tube S for drawing fluid from the ureter through thetube'or injecting uid through the tube into the ureter.

The apertures 10 and 11 are offset from one another as are the apertures8 and 9 so as to prevent weakening of the tube. The pairs of aperturespreferably are in offset but overlapping relation, that is an apertureof one pair are disposed longitudinally of the tube between the otherpair of apertures so that the loop 12 may be formed between either pairby traction on the respective str-and or the loop may be formed betweenthe intermediate portion of the tube between both pairs of apertures bytraction on both strands of the thread or wire 7. Moreover, the pairs ofapertures are offset circumferentially of the tube so that the tube andtwo strands can surround or engage a stone 4 at three points.

The loop 12 is of a suicient distance from the tip 6 of the tube 5 sothat the point of the tube will not reverse on itself. This is a veryimportant feature -as brought out in the objects of my invention.Another advantage of my extractor catheter is that a loop of any desiredsize can be formed, which is ideal in the expanding of the ureter in thetreatment of the same, or for the extraction of stones therefrom.Further, the said loop can be formedfeliminated or re-formed while inthe ureter.

What is claimed is:

l. A ureteral stone extractor comprising a flexible catheter tube, aninsertion tip on one end of said tube, said tube having two pairs ofapertures with one pair of apertures being closely spaced and adjacentsaid tip and the other pair of apertures being relatively widely spacedlongitudinally of said tube, and a thread-like element threaded throughsaid tube and anchored to said tube by passing through said one pair ofclosely spaced apertures and back through said tube, one strand of saidelement passing through said other pair of widely spaced apertures andoutside said tube between said latter pair of apertures, the aperture ofsaid latter pair nearest said tip being adjacent said tip but spacedtherefrom a distance suicient to prevent reverse bending or looping ofsaid tip, whereby traction on said element will cause said tube to curveor form a loop only between said latter pair of apertures for snaring ordislodging a calculus or dilating the ureter and without bending orlooping said tip.

2. A ureteral stone extractor as dened in claim l wherein said tube hastwo pairs of widely spaced apertures with the strands of said elementrespectively passing through said pairs of widely spaced apertures.

3. A ureteral stone extractor as dened in claim 2 wherein said aperturesof each widely spaced pair are spaced substantially a like distance fromeach other and the apertures of one pair are offset in overlappingrelation longitudinally of said tube with respect to the apertures ofthe other pair to preclude weakening of said tube.

References Cited in the le of this patent FOREIGN PATENTS 376,692 FranceJune 20, 1907 707,333 France Apr. 13, 1931 834,690 France Aug. 29, 1938

